Ali Zahid

ESLint for new projects

A reference store of my ESLint configurations for new projects
October 14, 2020
ESLint for new projects

I feel this config is a bit outdated. I haven't gotten around to updating this based on the new stuff I'm using so please use with caution.

I start new projects often, and I'm obsessive about doing them the right way. ESLint, Prettier, the works. Even if it's a single page Next.js site, every project needs to have all the bells and whistles, so things are perfectly consistent across all my code ever written.

This collection is still a work in progress while I tinker with things. Let's get started.

Prettier

I love Prettier. It's opinionated and gives me a fantastic base to get started. I use a pre-commit hook alongside Prettier to make sure anything missed gets formatted.

Before installing Husky, make sure you've created a Git repository first, or installing Git hooks will fail.

Install dependencies

yarn add --dev prettier\
  husky\
  pretty-quick

Prettier config — prettier.config.js

module.exports = {
  arrowParens: 'always',
  bracketSameLine: true,
  bracketSpacing: true,
  semi: false,
  singleQuote: true,
  trailingComma: 'none'
}

Setup Husky

npm set-script prepare "husky install"
yarn prepare

Precommit hook — .husky/pre-commit

yarn husky add .husky/pre-commit "yarn pretty-quick --staged"

ESLint

I rely on a lot of ESLint plugins to help lint my code. I'm obsessive about standards and consistency. Other than Prettier and standard ESLint / TypeScript rules, here are the things I need.

  • Imports should be grouped and sorted
  • Object (including destructured) keys should be sorted alphabetically
  • Component props should be sorted alphabetically

By using these rules, I can be certain that code across repositories will be consistent. But different types of projects require different rules and configurations. Let's break it down.

Node.js

Dependencies

yarn add --dev @typescript-eslint/eslint-plugin\
  @typescript-eslint/parser\
  eslint\
  eslint-config-prettier\
  eslint-plugin-prettier\
  eslint-plugin-simple-import-sort\
  eslint-plugin-sort-destructure-keys\
  eslint-plugin-sort-keys-fix

Script — package.json

eslint . --ext js,ts

Configuration — .eslintrc.json

{
  "extends": [
    "plugin:@typescript-eslint/recommended",
    "plugin:prettier/recommended"
  ],
  "parser": "@typescript-eslint/parser",
  "plugins": [
    "@typescript-eslint",
    "sort-keys-fix",
    "sort-destructure-keys",
    "simple-import-sort",
    "prettier"
  ],
  "rules": {
    "prettier/prettier": "error",
    "simple-import-sort/exports": "error",
    "simple-import-sort/imports": "error",
    "sort-destructure-keys/sort-destructure-keys": "error",
    "sort-keys-fix/sort-keys-fix": "error"
  }
}

Next.js

Dependencies

Next.js 12 only supports ESLint 7 for now.

yarn add --dev @typescript-eslint/eslint-plugin\
  @typescript-eslint/parser\
  eslint@7\
  eslint-config-next\
  eslint-config-prettier\
  eslint-plugin-prettier\
  eslint-plugin-simple-import-sort\
  eslint-plugin-sort-destructure-keys\
  eslint-plugin-sort-keys-fix

Script — package.json

next lint

Configuration — .eslintrc.json

{
  "env": {
    "browser": true,
    "node": true
  },
  "extends": [
    "next/core-web-vitals",
    "eslint:recommended",
    "plugin:@typescript-eslint/eslint-recommended",
    "plugin:@typescript-eslint/recommended",
    "plugin:prettier/recommended"
  ],
  "overrides": [
    {
      "files": ["*.js"],
      "rules": {
        "@typescript-eslint/no-var-requires": "off"
      }
    }
  ],
  "parser": "@typescript-eslint/parser",
  "plugins": [
    "@typescript-eslint",
    "sort-keys-fix",
    "sort-destructure-keys",
    "simple-import-sort",
    "prettier"
  ],
  "rules": {
    "@typescript-eslint/explicit-function-return-type": "off",
    "prettier/prettier": "error",
    "react/jsx-sort-props": "error",
    "react/prop-types": "off",
    "simple-import-sort/exports": "error",
    "simple-import-sort/imports": "error",
    "sort-destructure-keys/sort-destructure-keys": "error",
    "sort-keys-fix/sort-keys-fix": "error"
  },
  "settings": {
    "react": {
      "version": "detect"
    }
  }
}

React Native

Dependencies

yarn add --dev @react-native-community/eslint-config\
  @react-native-community/eslint-plugin\
  @typescript-eslint/eslint-plugin\
  @typescript-eslint/parser\
  eslint\
  eslint-config-prettier\
  eslint-plugin-prettier\
  eslint-plugin-react\
  eslint-plugin-react-hooks\
  eslint-plugin-react-native\
  eslint-plugin-simple-import-sort\
  eslint-plugin-sort-destructure-keys\
  eslint-plugin-sort-keys-fix

Script — package.json

eslint . --ext js,ts,tsx

Configuration — .eslintrc.json

{
  "extends": [
    "@react-native-community",
    "plugin:@typescript-eslint/eslint-recommended",
    "plugin:@typescript-eslint/recommended",
    "plugin:react-hooks/recommended",
    "plugin:prettier/recommended"
  ],
  "parser": "@typescript-eslint/parser",
  "plugins": [
    "@typescript-eslint",
    "react-hooks",
    "react-native",
    "react",
    "simple-import-sort",
    "sort-destructure-keys",
    "sort-keys-fix",
    "prettier"
  ],
  "rules": {
    "@typescript-eslint/explicit-member-accessibility": "off",
    "@typescript-eslint/explicit-module-boundary-types": "error",
    "@typescript-eslint/no-use-before-define": [
      "error",
      {
        "variables": false
      }
    ],
    "prettier/prettier": "error",
    "react-hooks/exhaustive-deps": "error",
    "react-hooks/rules-of-hooks": "error",
    "react-native/no-inline-styles": "error",
    "react-native/no-raw-text": "error",
    "react-native/no-unused-styles": "error",
    "react-native/split-platform-components": "error",
    "react/jsx-sort-props": "error",
    "simple-import-sort/exports": "error",
    "simple-import-sort/imports": "error",
    "sort-destructure-keys/sort-destructure-keys": "error",
    "sort-keys-fix/sort-keys-fix": "error"
  }
}

I'll keep updating this as I discover more useful stuff or remove redundant or incorrect stuff. If you have any suggestions, hit me up on Twitter.